Rectifier



May 5, 1931. E. A. QUARRIE `n RECTIFIER Filed June lO, 1927 jf/wantonPatented May 5, 1931 UNITED STATES TENT oramai.:

EUGENE A. QUARRIE, F NEW YORK, N. Y., ASSIGNOR TO C. E..1VIANUFACTURINGCO., 0F PROVIDENCE, RHODEV ISLAND, A CORPORATION OF RHODE ISLANDRECTIFIER Application filed June 10,

My invention relates to apparatus for rectifying alternating currentsand more particularly to such apparatus as depend upon the use of aconductive gas. The device of the present invention is :furthermore ofthe ficial area of the cathode to the anode and upon a proper shaping ofthe cathode with respect to the anode. The elicient life is,

furthermore, prolonged by maintaining the internal resistance of thecathode chamber at its initial low value.

When a proper proportion of these elements is observed, there is littledisintegration of the anode under the bombardment from the cathode.During disintegration ot metal parts a considerable quantity of gas isevolved which renders the conductive gas impure and produces adeleterious edect in that it increases the resistance of the cathodechamber. lVith increase of resistance a great deal of energy is lost asheat. Such gases as are evolved in the tube of the present inventionproduce no appreciable increase of resistance in the cathode chamber andare of such small quantity that they may it desired be neutralized inthe manner hereinafter set forth. Y Y i It is an object of the presentinvention to provide va device such as will have great elhciency duringa long life and which is characterized by a very rugged and strongsupporting structure. By properly correlating vthe cathode and anodes ofmy device, I ob- 1927. Serial No. 197,787.

tain a rectiiier Vwhich gives a very large output and in which becauseot the constant low internal resistance very little of the energy islost in the form of heat.

The invention will be better understood from the drawings to whichreference is now made f Fig. 1 shows the electrode structure of thedevice of my invention in sectional elevation.

Fig. 2 shows the elements comprising the cathode.

Fig. 3 shows the electrode structure mounted.

Similar reference numerals indicate similar parts in all the ligures.

In Fig. 1, one form of the device is lillustrated. It is a full waverectier and consists of a hermetically sealed bulb, 1, which is filledwith a. conductive monatomic gas such as helium or neon. The cathode isformed of two elements shown in Fig. 2, an upper part or cap, 2, theupper surface or which is curved outward on an arc rising to 1A; of aninch on a segment of one inch, the lower elementv is a cup, 3, overwhich the cap, 2, tits with a tight rictional tit. ln the bottom of thecup, 3, are two openings, 4 and 5, through which the tubular cathodesupports, 6 and 7, extend and which also receive the insulated rods, 8and 9. The supporting legs 6 and 7 of the cathode structure are formedof a conductive metal and are in eect a part of the cathode being in theform of hollow metallic tubes that form a passage for the anode rods, 8and 9, which are encased where they pass through said tubes ininsulating material such as glass, 11 and 12. The cathode and itssupports are shown in Figure 3, in which 2, shows a cap with small tabsor extensions, 13 and 14, on opposite sides. To these tabs are weldedthe cathode lead 15 and a support 16, which is anchored in the press ofthe stem.

lt will be observed therefore that the cathode is held by two sets ofsupporting elements comprising the tubular legs, 6 and 7 on the onehand, and the lead wire, 15, and the support, 16, on the other. It willalso be observed that both the lead wire, 15, and the support, 16, arein a plane at right angles to the plane of the tubular legs, 6 and 7, anarrangement which gives the device an exceptional strength andruggedness and enables it to withstand shocks incurred in the handlingand shipping.

Moreover, the anodes consist of metal rods, the uninsulated points orends of which project very slightly vinto the cathode chamber.

As previously pointed out the efficiency of a rectifier depends uponseveral considerations. In the first place, the interior space of thecathode chamber should bear a. proportionate relation to the size of theanodes. Assume that in the form of the invention shown in the, drawingthe cathode chamber is circular in plan having a diameter on the iioorthereof of approximately one inch. In such case I prefer to malte myanode in the form of a rod having al diameter of 0.06 and being composedof a conductive material such as nickel. I find that in a chamber of thesize mentioned by increasing the diameter of the anode above .06, I cancorrespond- Aingly increase the life of the tube, but at the expense ofefciency of rectification. Sirmlarly by decreasing the diameter of theanode, I can correspondingly increase the efciency of rectification butat the expense of life. For instance, with a cathode chamber of the sizementioned and an anode. of 2 mils diameter, I approximate perfectrectification but the life of the rectifier under these conditions isonly a few hundred hours. By increasing the diameter to 60 mils or .06inches, other relations remaining constant, I can obtain a currentoutput of 85 milliamperes for a period of from one to two thousandhours. I prefer, therefore, to employ anodes having ra d iameter in theneighborhood of six hundredths of an inch.

The cathode chamber should have a suiiicientlylarge superficial area onthe inside to afford a large emitting surface but this area is limitedby the necessity of keeping the internal resistance at a low value.Assuming that with a diameter of one inch, the cathode chamber had alsoa height of one inch, the

internal resistance of the cathode chamberwould be so great that theeiiiciency of rectitication would be very much impaired, de

spite the very large emitting surface. A@ cording to my invention, I soconstruct the cathode chamber that its interior supercial area will beregulated by balancing these two principles. It is thus evident, that bya proper balance between the interior superiicial area of the cathodeand the sizeof the anode, I can initially produce and, by the meansVhereinafter mentioned, effectively maintain the efficiency ofrectification and limit the heat loss to a constant low valu/e during aperiod of operation of the tube of fifteen hundred hours or more.

In the form of the invention shown in the drawings I preferably make thecathode in the form of a hollow chamber having a diameter of one inch, aheight at the sides of approximately -lg of an inch and I curve the topor roof thereof` upwards about 1/8 of an inch above the top of thesides; and the anode I form of a rod of a diameter of .06.

The proportions of cathode area and anode diameter may be varied togaingreater life at the expense of efficiency or greater etliciency at theexpense of life but I find the bestresults are obtained when theserelative proportions are observed. I do not, consequently, limit myselfto an anode having a diameter of .06 inch, for any structure having therelative proportions hereinabove indicated by the specific dimensionsgiven will be within the scope of my invention. Furthermore, thecurvature of the top of the cap serves to focus the electron stream uponthe anodes, since the electrons havev a tendency to move in a directionnormal to the emitting surface.

In operation of the device, the gas contained within the chamber, forexample, a monatomic gas, such as helium, becomesk highly ionized andthere is a considerable bombardment of the anodes. In such tubes thedesired action is a flow of electrons from the cathode to the anode andin the ideal case the anode should be infinitesimal in order to nullifythe effect of this bombardment. Prac- 100 tically, however, the anodehas to be of finite size. This results in a certain amount ofdisintegration of the metal of the anode, which tends to evaporate or toevolve gases. Such gases tend to increase the resistance of the 105 tubeand the increased resistance results in a loss of energy inthe form ofheat. The overheating of the metal parts in this manner still furtherpromotes the evaporation of the metal parts with very great injury bothto the 110 efficiency and life of the tubes. It should also be notedthat the nature of the metal forming the anode also has a bearing on theamount of disintegration and on the amount of gases evolved.

I have previously explained that by properly proportioning the cathodeand anode, I am enabled to reduce this effect to very small proportionsregardless of other considerations; It cannot, however, for reasonsabove 120 stated be wholly eliminated. I, therefore, enclose within thecathode chamber a small quantity of cerium and calcium in a metallicstate and either in the form of a powder or as a'small pellet of analloy of these metals. 125 During the operation of the tube these metalsgive oil' gases at a comparatively low temperature and these gases arenot only advantageous in adding to the conductivity Vof the heliumbutthey also combine with foreign 130 gases that may be liberated fromthe interior parts of the tube, rendering them harmless. Careful testshave shown that the device constructed according to the principles ofthis invention is capable of producing a very large output current andvoltage and that the device has little tendency to become overneatedwhich is a great defect in most rectifiers of this type, in which alarge proportion of the energy is dissipated as heat.

Having thus described my invention, what I claim is l. A rectifiercomprising a sealed glass envelope, a closed hollow cathode, anodesconsisting of rods, the points of which project within said cathode, aconductive gas within said envelope and said cathode, conductive tubularsupports for the cathode and auxiliary cathode supports lying in a.plane substantially at right angles to the plane of the tubularsupports.

2. A rectilier tube comprising a sealed glass envelope, a hollow cathodeand two rod shaped anodes the points of which project within saidcathode, a cathode structure consisting of a cup shaped element, a captting thereon with a tight rictional fit, two metallic supporting legsreceiving said rod shaped anodes and, in a plane at right angles to saidsupporting legs, an auxiliary system of supports consisting of thecathode lead and another supp orting wire; said cathode structure beingmounted upon a stem forming part of said envelope.

3. In a rectifying tube, a cathode consisting of a cup-shaped elementsupported by metallic legs and a cap having a frictional lit on saidelement; and rod-shaped anodes insulated within said metallic legs.

4. A rectifying tube comprising a hollow cathode within which therectifying action is confined, an anode consisting of a rod, the pointof which is presented to the interior of the chamber formed by saidhollow cathode a conductive gas within said chamber and a quantity ofmetallic cerium and calcium adapted to give off vapors during operationof said tube which vapors coact with deleterious vapors within saidchamber thereby maintaining the resistance of said cathode chamber at aconstant low value.

5. In a rectifying tube a cathode comprising a hollow chamber withinwhich the rectifying action is to be confined mounted upon supportingconductive legs, anodes consisting of rods insulated within said legs,the points of said anodes being presented within said hollow cathodechamber, a conductive gas within said hollow cathode chamber and meansalso within said chamber for maintaining the resistance of said chamberat a constant low value.

6. In a rectifying tube, a cathode comprising a hollow chamber, withinwhich the rectifying action is to be conned, mounted upon a supportingconductive leg, an anode consistmg of a rod insulated within said leg,the point of said anode being presented within said hollow cathodechamber, a conductive gas within said hollow cathode chamber, and meansalso within said chamber for maintaining th-e resistance of said chamberat a constant low value.

In witness whereof, I have hereunto set my hand, on this 7th day ofJune, in the year one thousand nine hundred and twentyseven.

yEUGENE A. QUARRIE.

